The invention relates to a dredge pump, consisting of a volute pump casing, with a lateral, round suction opening and with an outlet, in which pump casing an impeller is mounted which consists of a front plate with an opening adjoining the suction opening of the pump casing, of a back plate which is connected to a drive shaft supported in the pump casing and coupled to a motor, and of two blades extending between the front plate and the back plate and connecting these to each other, one of which blades, which has at least substantially the form of a circular arc at its end nearest the axis of rotation and subsequently increases in radius, forms a passage which is connected through the opening in the front plate to the suction opening of the pump casing and which is passed in the direction of its lateral outlet by all dredged material which is to be pumped, one end of the second blade adjoining the aforementioned end of the first blade radially on the outside and the other end of this second blade lying at least substantially diametrically opposite the other end of the first blade, the two blades, viewed from the axis of rotation, having a concave curvature.
Prior art embodiments of such dredge pumps frequently have the disadvantage of becoming very rapidly clogged, especially when pumping dredged material comprising large solid pieces, such as, for example, stones and lumps of peat or clay, and or containing a great deal of vegetation.